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Yeah, as previously said, you should put tape or paint on the metallic surface to measure its temperature with your thermal camera.
In my engineering school we did an experiment to measure the emissivity of different type of surfaces .

We could see that without entering the emissivity values, the IR camera would show 64°c for a polished metal plate even if the real temperature (measured with a thermo-couple sticked to the surface) was 74°c .

Infrared cameras measure the temperature by measuring the amount of infrared radiation emitted by a surface. But metal surfaces inherently emit less (it had low emissivity) so the infrared camera reads low. Try putting a temperature sensor (RTD, thermistor or thermocouple) on the metal and it should read 105C. Or put a dab of paint or piece of tape on the metal and aim the IR camera at that.

> Are either of these processes related to the pressure of the mass above? I always thought that was what caused the heat.

No. The mass above plays a role in the sense that it dictates the rates of heat transfer toward the surface from a given depth, but the fact that it's under pressure does not directly generate heat. There are various depth/pressure/temperature related processes that occur, specifically phase transitions at specific depth/pressure/temperature ranges that do change heat content, e.g., the 660 transition is characterized by an endothermic reaction and thus does contribute to the total heat budget.

> 1. Is radioactive decay triggered by something or does it just happen with those particular elements?

Radioactive decay, and its rate, is an intrinsic property of a given isotope. There is abundant literature and details on radioactive decay, but generally speaking, for a given isotope (e.g., ^(238)U, which is one that is relevant for the question), the "rate" of decay is actually a reflection that there is a fixed probability that any given 238 atom will decay, and given an arbitrarily large group of 238 atoms, we can consider this as a rate of decay.

> Is there something besides the insulating qualities of the crust that keep primordial heat from cooling quicker.

Insulating qualities of the entire planet, i.e., rock is not a great conductor, the relative inefficiency of radiation as a heat transfer mechanism (i.e., how heat is ultimately transferred out of the solid Earth), and the radioactive decay all play an important role. For the last bit, it's not just that radioactive decay is adding heat, but also in doing so, it's effectively slowing down the rate of heat loss. Broadly speaking, the rate of heat transfer is related to the gradient in temperature. Thus a reduced gradient (because the interior stays warmer) means that the rate of heat transfer is less. Things get more complicated as we have to think about convective heat transfer in the outer core and mantle, but broadly this point remains true.

That scandal is fascinating and sad at the same time. The lengths some academics will go to to get grant funding and beat their colleagues is insane. You have to wonder how widespread it is. Also, crazy that he had a massive lawsuit brewing and then died in 2013... one has to wonder if it was self-harm, stress, or some other related thing. Das would have us to believe it was an assassination by the pharma industry...

Scientists use a variety of analytical methods to study the evolution of viruses and to determine their age. These include sequencing the genetic material of the virus, analyzing the virus's structure, and studying the virus's evolutionary relationship with other known viruses. By studying these factors, scientists can piece together an estimate of the age of the virus. Additionally, researchers have developed mathematical models to estimate the age of a virus based on its rate of genetic change.

What are mathematical models to estimate the age of a virus?
Depending on the type of virus, there are various mathematical models that can be used to estimate the age of a virus. For example, for RNA viruses, the substitution rate can be used to estimate the age. For DNA viruses, the substitution rate can also be used, but there are other methods, such as the coalescent model, which can also provide an estimate. In addition, the molecular clock hypothesis can be used to estimate the amount of time that has passed since the virus diverged from a common ancestor. Ultimately, the best model to use depends on the type of virus, but there are a variety of mathematical models that can be used to estimate its age.

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No, black holes aren't considered stars. Those super massive ones are enormous, though - the radius is linear to mass, and a 1 solar mass black hole has a radius of 3 km. So a 40 billion solar mass black hole would have a radius of about 120 billion km! Which is about 20 times further out than Pluto is, on average.

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In addition: There's special paint to measure the temperature of normally reflective surfaces.

Yes, he just sees a colder environment (assuming door is open) reflected on the metal.

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The increase of pressure occurred billions of years ago when the Earth was originally formed from the cloud of gas and dust accumulated in a disc around the early Sun.

The collisions between particles created a lump that started attracting more and more particles and dust and larger debris pieces. As the mass increased, gravity also increased and each layer started to push on the layer under it with increasing weight. Eventually the force of gravity was strong enough to slowly deform the core of the object, until the proto-Earth reached a state called hydrostatic equilibrium.

In English this means the object was now big enough that it formed into a sphere under its own weight. This shape change caused a lot of heat through friction, and of course the Earth was not yet done growing.

As the planet grew and the pressure within increased, the core started to melt, which meant that heavy elements sunk into the core. However, eventually the planet grew so big that the pressure at the core actually started to solidify the iron and nickel there.

This is how Earth ended up with a solid iron-nickel inner core, surrounded by a thick layer of outer core which is also mostly iron and nickel, but in liquid phase.

So, the pressure increase that caused the Earth's core to heat up originally occurred billions of years ago when the planet was forming.

Currently, it's believed that some of Earth's core heat is still residual or "primordial" heat from the formation of the planet, and the rest is from tidal forces generated by the Moon, or heat from radioactive decay of active isotopes.

thank you for this correction/clarification

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There is a difference between the inner and outer core. The inner core is approximately solid while the outer core is liquid and is the region that produces the geodynamo. The geomagnetic reversals are more related to the fluid motion in the outer core than the rotation (and/or differential rotation) of the inner core.

Yes to be fair I have missed the gravitational coupling between inner core and mantle (actually I was not overly aware of it as I am more on the astro than geo side of fluid dynamics, so my interactions with deep earth people tend to be where there is over lap, i.e. dynamo theory).

I'm confused. Are either of these processes related to the pressure of the mass above? I always thought that was what caused the heat. Two more questions. 1. Is radioactive decay triggered by something or does it just happen with those particular elements? 2. Is there something besides the insulating qualities of the crust that keep primordial heat from cooling quicker. Billions of years seems like a long time for something to cool down. I know it is a lot of mass but......

Are black holes considered stars? If they are, I was just reading a few days ago about the largest black hole/quaser/blazer ever found with a mass of 40 billion suns. How big or what is the size of a black hole of that mass can be? Is it bigger than the solar system?

Think more "mars-scape, marscape?", as the core also gives us our magnetic field that protects our atmosphere from the solar winds. Once the core cools, the Earth's internal dynamo also slows, solar winds start buffeting our atmosphere out of Earth's gravitational field, and we start looking more like Mars.

Also scheduled to happen around the same geologic time as the Earth being swallowed / burned by the Sun.

Thermal cameras aren't that great at accurately measuring temperature particularly when comparing different materials. The emissivity of the metal with be very different to that of the other materials and so a different temperature will be measured.

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